This invention relates to quality control in manufacturing operations, and more particularly to apparatus for checking a sequence of manufactured elements for conformity to predetermined dimensional, configuration or orientation standards.
Where large numbers of similar elements such as machine parts are manufactured or otherwise processed, it is often necessary to check each successive part for conformity to some predetermined configuration along one or more dimensions of the part or to check for parts which may be misoriented relative to the others. This may variously be necessary in order to eliminate defective parts or to initiate operation of automatic machinery for correcting some detected dimensional or positional irregularity. In many instances it is unduly time consuming or costly to do this manually using simple measuring tools. Most such purely manual techniques rely upon visual tactile or other sensing operations by workmen. As a result, distractions, fatique or the like can cause occasional errors and detract from the general reliability of the checking process.
In order to provide for more rapid, efficient and reliable monitoring of manufactured parts, a variety of automatic checking devices have heretofore been developed. In general, these are undesirably complex and costly. Typically, such devices require movable mechanical sensing elements for checking dimensions or configurations of each part, as well as electrical circuits for detecting dimensional deviations on the basis of movements of the mechanical sensors. Such mechanisms are subject to wear, jamming and other malfunctions, and may be difficult to adjust.